EP0743342A1 - ABS thermoplastic mouldings - Google Patents

Abstract

Thermoplastic moulding materials (I), contg. (A) 5-95 pts. wt. particulate graft copolymer(s) of the ABS type obtd. by emulsion polymerisation, in which the graft rubber particles, as observed by transmission electron microscopy, show non-uniform cellular inclusions of resin-forming polymer and an irregularly serrated surface with 5-30 spikes per particle, with a particle dia. of d + d/x, where d = the dia. of an ideal round particle and x = 3-15; (B) 95-5 pts. wt. of other emulsion ABS copolymer(s) consisting of round particles with an entirely unserrated surface and no pronounced internal structure; and opt. (C) 0-300 pts. wt. thermoplastic rubber-free resin(s). Pref. (I) contains 10-80 pts. wt. (A) with 7-25 spikes/particle and a particle dia. of d + d/x, where x = 4-12, plus 90-20 pts. wt. (B) as above and opt. 20-250 pts. wt. (C). The graft copolymer rubbers consist of polybutadiene grafted with styrene/acrylonitrile copolymer. (C) comprises styrene/acrylonitrile (SAN) copolymer, alpha -methylstyrene/acrylonitrile copolymer, aromatic polycarbonate, aromatic polyester-carbonate, polyester and/or polyamide.

Description

ABS molding compounds have been used in large quantities for years as thermoplastic resins for the production of all types of molded parts. The properties of these resins range from relatively brittle to very tough.

A special area of application for ABS molding compounds is the production of molded parts with high demands on toughness when subjected to impact, especially at low temperatures, as well as the possibility of specifically setting the surface hardness or the modulus of elasticity (e.g. production of parts with high rigidity and good scratch resistance in the automotive sector or in the manufacture of housing parts) with very good thermoplastic processability while maintaining the other ABS-typical properties (e.g. good surface gloss, good heat resistance).

One way to achieve these properties is to use ABS polymers in which the rubber phase has a special serrated structure (see German patent application P 441 846.9). However, when these polymers are used in the production of colored molded parts with rib structures, there may be a color deepening behind the ribs, which gives the impression of an uneven coloring.

It was therefore an object to provide molding compositions which, while largely maintaining the abovementioned good properties, do not cause any color deepening.

It has been found that products with the property combinations described above can be adjusted by means of a special combination of ABS polymers produced by emulsion polymerization with special structures, without a disturbing color deepening occurring behind the ribs.

• A) 5 bis 95 Gew.-Teile, vorzugsweise 10 bis 80 Gew.-Teile und besonders bevorzugt 15 bis 70 Gew.-Teile mindestens eines durch Emulsionspolymerisation hergestellten teilchenförmigen Pfropfkautschukpolymeren vom ABS-Typ, bei dem die Pfropfkautschukteilchen eine solche über transmissionselektronenmikroskopische Aufnahmen detektierbare Struktur aufweisen, in der die einzelnen Teilchen ungleichmäßige zellenförmige Einschlüsse von harzbildendem Polymer enthalten und die Oberfläche der Teilchen eine solche unregelmäßig gezackte Struktur zeigt, daß pro abgebildetem Teilchen 5 bis 30, vorzugsweise 7 bis 25 und besonders bevorzugt 10 bis 20 solcher Zacken vorhanden sind, die sich von einem idealisierten runden Teilchen (mit einem Durchmesser d) durch einen Durchmesser $\text{d + d/x mit x = 3 bis 15}$
  
  , vorzugsweise 4 bis 12 und besonders bevorzugt 5 bis 10, unterscheiden,
• B) 95 bis 5 Gew.-Teile, vorzugsweise 90 bis 20 Gew.-Teile und besonders bevorzugt 85 bis 30 Gew.-Teile mindestens eines durch Emulsionspolymerisation hergestellten teilchenförmigen Pfropfkautschukpolymeren vom ABS-Typ, bei dem die Pfropfkautschukteilchen eine solche über transmissionselektronenmikroskopische Aufnahmen detektierbare Struktur aufweisen, in der die einzelnen Teilchen keine ausgeprägte Innenstruktur wie in A) aufweisen und eine runde Teilchenform mit völlig zackenfreier Oberfläche zeigen und gegebenenfalls
• C) 0 bis 300 Gew.-Teile, vorzugsweise 20 bis 250 Gew.-Teile und besonders bevorzugt 50 bis 200 Gew.-Teile mindestens eines thermoplastischen kautschukfreien Harzes.

The invention relates to thermoplastic molding compositions containing:

• A) 5 to 95 parts by weight, preferably 10 to 80 parts by weight and particularly preferably 15 to 70 parts by weight of at least one particulate graft rubber polymer of the ABS type produced by emulsion polymerization, in which the graft rubber particles detect one such via transmission electron micrographs Have a structure in which the individual particles contain irregular cellular inclusions of resin-forming polymer and the surface of the particles shows such an irregularly jagged structure that there are 5 to 30, preferably 7 to 25 and particularly preferably 10 to 20 such jags per particle shown, which differs from an idealized round particle (with a diameter d) by a diameter $\text{d + d / x with x = 3 to 15}$
  
  , preferably 4 to 12 and particularly preferably 5 to 10,
• B) 95 to 5 parts by weight, preferably 90 to 20 parts by weight and particularly preferably 85 to 30 parts by weight of at least one particulate graft rubber polymer of the ABS type produced by emulsion polymerization, in which the graft rubber particles detect such particles via transmission electron micrographs Have structure in which the individual particles do not have a pronounced internal structure as in A) and have a round particle shape with a completely jag-free surface and optionally
• C) 0 to 300 parts by weight, preferably 20 to 250 parts by weight and particularly preferably 50 to 200 parts by weight of at least one thermoplastic rubber-free resin.

The graft rubber polymer A) is prepared by emulsion polymerization of resin-forming monomers in the presence of the rubber in latex form.

For this purpose, preferably 40 to 90 parts by weight, particularly preferably 45 to 85 parts by weight and very particularly preferably 50 to 80 parts by weight of a resin-forming monomer (preferably a mixture of styrene and acrylonitrile, which, if appropriate can contain up to 50% by weight (based on the total amount of the monomers used in the graft polymerization) of one or more comonomers) in the presence of 10 to 60 parts by weight, preferably 15 to 55 parts by weight and particularly preferably 20 to 50 parts by weight (each calculated as a solid) of a rubber latex (preferably polybutadiene latex) with a swelling index ≧ 30, preferably ≧ 40 and particularly preferably ≧ 50 (in toluene) polymerized in such a way that during 25 to 90%, preferably 30 to 80% and particularly preferably 35 to 75% of the total reaction time in the reaction mixture an amount of 5 to 70% by weight, preferably 7.5 to 60% by weight and particularly preferably 10 to 50% by weight (based on the total up to the respective point in time) monomer used) is present on unreacted monomer.

As rubbers for producing the graft rubber polymer A), those with a glass transition temperature below 0 ° C. are preferably used.

• Dienkautschuke, das heißt, Homopolymerisate von konjugierten Dienen mit 4 bis 8 C-Atomen wie Butadien, Isopren, Chloropren oder deren Copolymerisate mit bis zu 60 Gew.-%, bevorzugt 1 bis 30 Gew.-%, eines Vinylmonomeren, z.B. Acrylnitril, Methacrylnitril, Styrol, α-Methylstyrol, Halogenstyrole, C₁-C₄-Alkylstyrole, C₁-C₆-Alkylacrylate und -methacrylate, Alkylenglykoldi-acrylate und -methacrylate sowie Divinylbenzol;
• Acrylatkautschuke, das heißt, Homo- und Copolymerisate von C₁-C₁₀-Alkylacrylaten, z.B. Homopolymerisate von Ethylacrylat, Butylacrylat, 2-Ethylhexylacrylat oder Copolymerisate mit bis zu 40 Gew.-%, bevorzugt nicht mehr als 10 Gew.-% Mono-Vinylmonomeren, z.B. Styrol, Acrylnitril, Vinylbutylether, Acrylsäure(ester), Methacrylsäure(ester), Vinylsulfonsäure. Bevorzugt werden solche Acrylatkautschukhomo- bzw. -copolymerisate eingesetzt, die 0,01 bis 8 Gew.-% Divinyl- oder Polyvinylverbindungen und/oder N-Methylolacrylamid- (oder -methacrylamid)-Derivate enthalten, die als Vernetzer wirken, z.B. Divinylbenzol, Triallylcyanurat und wobei der Kautschuk C=C-Doppelbindungen enthält;
• Terpolymer-Kautschuke, das heißt, Copolymerisate aus mono-olefinischen Kohlenwasserstoffen, z.B. Ethylen, Propylen und Diene, z.B. Butadien, Cyclopentadien.

The following are suitable, for example:

• Diene rubbers, that is, homopolymers of conjugated dienes with 4 to 8 carbon atoms such as butadiene, isoprene, chloroprene or their copolymers with up to 60% by weight, preferably 1 to 30% by weight, of a vinyl monomer, for example acrylonitrile, methacrylonitrile , Styrene, α-methylstyrene, halostyrenes, C ₁ -C ₄ alkylstyrenes, C ₁ -C ₆ alkyl acrylates and methacrylates, alkylene glycol diacrylates and methacrylates and divinylbenzene;
• Acrylate rubbers, that is, homopolymers and copolymers of C ₁ -C ₁₀ -alkyl acrylates, for example homopolymers of ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate or copolymers with up to 40% by weight, preferably not more than 10% by weight, of mono- Vinyl monomers, for example styrene, acrylonitrile, vinyl butyl ether, acrylic acid (ester), methacrylic acid (ester), vinyl sulfonic acid. Those acrylate rubber homopolymers or copolymers which contain 0.01 to 8% by weight of divinyl or polyvinyl compounds and / or N-methylolacrylamide (or methacrylamide) derivatives which act as crosslinking agents, for example divinylbenzene, triallyl cyanurate, are preferably used and wherein the rubber contains C = C double bonds;
• Terpolymer rubbers, that is, copolymers of mono-olefinic hydrocarbons, for example ethylene, propylene and dienes, for example butadiene, cyclopentadiene.

Polybutadiene rubbers and SBR rubbers with up to 30% by weight of copolymerized styrene are preferred, and polybutadiene is particularly preferred.

The rubber polymers to be used for the preparation of the graft rubber polymer A) have swelling indices (in toluene) ≧ 30, preferably ≧ 40 and particularly preferably ≧ 50. The swelling indices are determined as follows:

1 g of dry stabilized chopped rubber is mixed with 100 cm ^{3 of} toluene and shaken in a brown bottle for 24 h. Then it is suctioned off through a double cloth filter until the filtrate has no more precipitate. After washing with additional toluene, the precipitate is weighed wet. Then it is dried to constant weight at 70 ° C. in a drying cabinet and weighed again. The swelling index (QI) results from the ratio $$\text{QI =}\frac{\text{Precipitation (wet)}\hfill }{\text{Precipitation (dry)}\hfill }\text{.}$$

The production of rubbers with such swelling indices is known in principle; the required values are set by using suitable reaction conditions (e.g. low reaction temperature or the addition of molecular weight regulators such as mercaptans).

The size of the rubber particles to be used for producing the graft rubber polymer A) can be varied within wide limits, for example average particle diameters of approximately 50 nm to approximately 500 nm are possible in principle; rubber particles with average diameters of approx. 200 nm to approx. 400 nm are preferred, particularly preferred from approx. 250 nm to approx. 350 nm. Here mean particle diameters mean d ₅₀ values which can be determined by ultracentrifuge measurement (cf. W. Scholtan and H Lange was determined in Kolloid-Z and Z. Polymer 250 , pp. 782-796 (1972).

The usual anionic emulsifiers such as alkyl sulfates, alkyl sulfonates, aralkyl sulfonates, soaps of alkaline disproportionated or hydrogenated abietic or tall oil acids, soaps of saturated or unsaturated fatty acids, emulsifiers based on compounds with cyclic hydrocarbon skeletons according to DE-OS 3 919 548 and DE-OS 3 can be used as emulsifiers 925 634 are used, preferably emulsifiers with carboxyl groups (for example salts of C ₁₀ -C ₁₈ fatty acids, salts of disproportionated abietic acid) are used.

, vorzugsweise 4 bis 12 und besonders bevorzugt 5 bis 10, unterscheiden.The structure of the graft rubber particles A) can be determined by transmission electron microscopy (e.g. after contrasting with osmium tetroxide, see e.g. JA Manson, LH Sperling: Polymer Blends and Composites (Plenum Press, New York / London, 1976), pp. 57-58 and cited there Literature) can be detected. The graft rubber particles A) in the electron micrographs (that is, in the image of the cut surface) must contain irregular cellular inclusions of the resin-forming polymer and show an irregularly jagged structure on the particle surface. There must be 5 to 30, preferably 7 to 25 and particularly preferably 10 to 20 points per particle, which differ from an idealized round particle (with a particle diameter d) by a diameter $\text{d + d / x with x = 3 to 15}$

, preferably 4 to 12 and particularly preferably 5 to 10.

Schematic:

The graft rubber polymer B) is prepared by emulsion polymerization of resin-forming monomers in the presence of the rubber in latex form. The graft rubber polymers B) preferably have rubber contents of 30 to 80% by weight, particularly preferably 35 to 75% by weight and very particularly preferably 40 to 70% by weight.

The production of such products with graft rubber particles without a pronounced internal structure with a jag-free surface is known and is described in detail in the patent literature (cf. e.g. DE 24 20 357, DE 24 20 358, DE 35 23 312, DE 33 37 940); Commercial ABS products based on emulsion polymers usually contain graft rubbers of this type as impact modifiers.

As rubbers for producing the graft rubber polymer B), those with a glass transition temperature below 0 ° C. are preferably used.

Suitable are e.g. the rubbers mentioned in the production of A). Polybutadiene rubbers and SBR rubbers with up to 30% by weight of copolymerized styrene are also preferred for the preparation of the graft rubber polymers B); polybutadiene is particularly preferred.

The swelling indices of the rubber polymers to be used for the production of the graft rubber polymers B) are not critical; they can be, for example, between approximately 10 and 80.

The graft copolymerization reaction in the production of the graft rubbers B) is preferably carried out by uniformly reacting the monomers over the entire course of the reaction.

The size of the rubber particles to be used for the production of the graft rubber polymer B) can be varied within wide limits, for example average particle diameters of approximately 50 nm to approximately 500 nm are possible in principle; preferred are rubber particles with average diameters from approx. 70 nm to approx. 150 nm and from approx. 200 nm to approx. 480 nm, particularly preferred from approx. 80 nm to approx. 140 nm and from approx. 300 nm to approx. 450 nm mean mean particle diameter d ₅₀ values, which were determined by ultracentrifuge measurement (cf. W. Scholtan and H. Lange in Kolloid Z. and Z. Polymer 250 , pp. 782 to 796 (1972).

Resin-forming monomers used in the preparation of the graft rubber polymer B) are preferably compounds having a vinyl group, for example styrene, C ₁ -C ₄ -alkyl-substituted styrenes, α-methylstyrene, acrylonitrile, methacrylonitrile, esters of acrylic acid and / or methacrylic acid with C ₁ -C ₈ -aliphatic or cycloaliphatic Alcohols, N-substituted maleimide or mixtures thereof. Mixtures of styrene and acrylonitrile, preferably in a weight ratio of 60:40 to 80:20, are particularly preferred, styrene and / or acrylonitrile being able to be partially replaced by copolymerizable monomers, preferably by α-methylstyrene, methyl methacrylate or N-phenylmaleimide.

Molecular weight regulators can also be used here, preferably in amounts of 0.05 to 2% by weight, particularly preferably in amounts of 0.1 to 1% by weight (in each case based on the total amount of monomers in the graft polymerization reaction). Suitable molecular weight regulators are, for example, n-dodecyl mercaptan, t-dodecyl mercaptan, dimeric α-methylstyrene.

The compounds and temperatures described in the preparation of the graft rubber polymer A) and the temperatures described in the preparation of the graft rubber polymer B) can also be used as initiators and emulsifiers and in the choice of the reaction temperature.

The graft rubber particles B) do not have to have a pronounced internal structure (such as graft rubber polymer A) and a round particle shape (ideally, possibly slightly asymmetrically distorted round particle shape) with a completely jag-free surface in the electron microscopic images (i.e. in the illustration of the cut surface).

Possible additional thermoplastic rubber-free resin components C) that may be used include:
Styrene / acrylonitrile copolymers, α-methylstyrene / acrylonitrile copolymers, styrene / α-methylstyrene / acrylonitrile terpolymers, styrene / methyl methacrylate copolymers, methyl methacrylate / acrylonitrile copolymers, polymethyl methacrylate, styrene / acrylonitrile / N-phenylmaleinimate for the preparation of details these resins are described, for example, in DE-AS 2 420 358 and DE-AS 2 724 360. Vinyl resins produced by bulk or solution polymerization have proven particularly useful.

In addition to such thermoplastic resins composed of vinyl monomers, it is also possible to use, for example, aromatic polycarbonates, aromatic polyester carbonates, polyesters, polyamides as resin component C).

worin

A

eine Einfachbindung, C₁-C₅-Alkylen, C₂-C₅-Alkyliden, C₅-C₆-Cycloalkyliden, -O-, -S-, -SO-, -SO₂- oder -CO- ist,

R⁵ und R⁶

unabhängig voneinander für Wasserstoff, Methyl oder Halogen, insbesondere für Wasserstoff, Methyl, Chlor oder Brom stehen,

R¹ und R²

unabhängig voneinander Wasserstoff, Halogen bevorzugt Chlor oder Brom, C₁-C₈-Alkyl, bevorzugt Methyl, Ethyl, C₅-C₆-Cycloalkyl, bevorzugt Cyclohexyl, C₆-C₁₀-Aryl, bevorzugt Phenyl, oder C₇-C₁₂-Aralkyl, bevorzugt Phenyl-C₁-C₄-alkyl, insbesondere Benzyl, bedeuten,

m

eine ganze Zahl von 4 bis 7, bevorzugt 4 oder 5 ist,

n

0 oder 1 ist,

R³ und R⁴

für jedes X individuell wählbar sind und unabhängig voneinander Wasserstoff oder C₁-C₆-Alkyl bedeuten und

X

Kohlenstoff bedeutet,

mit Kohlensäurehalogeniden, vorzugsweise Phosgen, und/oder mit aromatischen Dicarbonsäuredihalogeniden, vorzugsweise Benzoldicarbonsäuredihalogeniden, nach dem Phasengrenzflächenverfähren oder mit Phosgen nach dem Verfahren in homogener Phase (dem sogenannten Pyridinverfahren), wobei das Molekulargewicht in bekannter Weise durch eine entsprechende Menge an bekannten Kettenabbrechern eingestellt werden kann.Suitable thermoplastic polycarbonates or polyester carbonates are known (cf., for example, DE-AS 1 495 626, DE-OS 2 232 877, DE-OS 2 703 376, DE-OS 2 714 544, DE-OS 3 000 610, DE-OS 3 832 396, DE-OS 3 077 934), for example can be prepared by reacting diphenols of the formulas (I) and (II)

wherein

A

is a single bond, C ₁ -C ₅ alkylene, C ₂ -C ₅ alkylidene, C ₅ -C ₆ cycloalkylidene, -O-, -S-, -SO-, -SO ₂ - or -CO-,

R ⁵ and R ⁶

independently of one another represent hydrogen, methyl or halogen, in particular hydrogen, methyl, chlorine or bromine,

R ¹ and R ²

independently of one another hydrogen, halogen preferably chlorine or bromine, C ₁ -C ₈ alkyl, preferably methyl, ethyl, C ₅ -C ₆ cycloalkyl, preferably cyclohexyl, C ₆ -C ₁₀ aryl, preferably phenyl, or C ₇ -C _12- aralkyl, preferably phenyl-C ₁ -C ₄ -alkyl, in particular benzyl,

m

is an integer from 4 to 7, preferably 4 or 5,

n

Is 0 or 1,

R ³ and R ⁴

are individually selectable for each X and independently of one another are hydrogen or C ₁ -C ₆ -alkyl and

X

Carbon means

with carbonic acid halides, preferably phosgene, and / or with aromatic dicarboxylic acid dihalides, preferably benzenedicarboxylic acid dihalides, after the phase interface process or with phosgene according to the process in homogeneous phase (the so-called pyridine process), the molecular weight being able to be adjusted in a known manner by an appropriate amount of known chain terminators .

Suitable diphenols of the formulas (I) and (II) are e.g. Hydroquinone, resorcinol, 4,4'-dihydroxydiphenyl, 2,2-bis (4-hydroxyphenyl) propane, 2,4-bis (4-hydroxyphenyl) -2-methylbutane, 2,2-bis (4- hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3- dimethylcyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5,5-tetramethylcyclohexane or 1,1-bis (4-hydroxyphenyl) -2,4,4, -trimethylcyclopentane.

Preferred diphenols of the formula (I) are 2,2-bis (4-hydroxyphenyl) propane and 1,1-bis (4-hydroxyphenyl) cyclohexane, preferred phenol of the formula (II) is 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane.

Mixtures of diphenols can also be used.

Suitable chain terminators are, for example, phenol, p-tert-butylphenol, long-chain alkylphenols such as 4- (1,3-tetramethyl-butyl) phenol according to DE-OS 2 842 005, monoalkylphenols, dialkylphenols with a total of 8 to 20 carbon atoms in the alkyl substituents according to DE-OS 3 506 472, such as p-nonylphenol, 2,5-di-tert.-butylphenol, p-tert.-acrylicphenol, p-dodecylphenol, 2- (3,5-dimethylheptyl) phenol and 4- ( 3,5-dimethylheptyl) phenol. The amount of chain terminators required is generally 0.5 to 10 mol%, based on the sum of the diphenols (I) and (II).

The suitable polycarbonates or polyester carbonates can be linear or branched; branched products are preferably by the incorporation of 0.05 to 2.0 mol%, based on the sum of the diphenols used, of three - or more than three-functional compounds, e.g. those with three or more than three phenolic OH groups.

The suitable polycarbonates or polyester carbonates can contain aromatically bound halogen, preferably bromine and / or chlorine; they are preferably halogen-free.

_w, Gewichtsmittel) bestimmt z.B. durch Ultrazentrifugation oder Streulichtmessung von 10 000 bis 200 000, vorzugsweise von 20 000 bis 80 000.They have average molecular weights ( $\overline{\text{M}}$

_w , weight average) determined, for example, by ultracentrifugation or scattered light measurement from 10,000 to 200,000, preferably from 20,000 to 80,000.

Suitable thermoplastic polyesters are preferably polyalkylene terephthalates, that is, reaction products made from aromatic dicarboxylic acids or their reactive derivatives (e.g. dimethyl esters or anhydrides) and aliphatic, cycloaliphatic or arylaliphatic diols and mixtures of such reaction products.

Preferred polyalkylene terephthalates can be prepared from terephthalic acids (or their reactive derivatives) and aliphatic or cycloaliphatic diols with 2 to 10 carbon atoms by known methods (Kunststoff-Handbuch, Volume VIII, p. 695 ff, Carl Hanser Verlag, Munich 1973).

Preferred polyalkylene terephthalates contain 80 to 100, preferably 90 to 100 mol% of the dicarboxylic acid residues, terephthalic acid residues and 80 to 100, preferably 90 to 100 mol% of the diol residues, ethylene glycol and / or 1,4-butanediol residues.

The preferred polyalkylene terephthalates can contain, in addition to ethylene glycol or 1,4-butanediol residues, 0 to 20 mol% of residues of other aliphatic diols with 3 to 12 C atoms or cycloaliphatic diols with 6 to 12 C atoms, for example residues of propanediol 1,3, 2-ethyl propanediol-1,3, neopentyl glycol, pentanediol-1,5, hexanediol-1,6, cyclohexanedi-methanol-1,4, 3-methylpentanediol-1,3 and -1,6, 2-ethylhexanediol -1,3, 2,2-diethylpropanediol-1,3, hexanediol-2,5, 1,4-di (β-hydroxyethoxy) benzene, 2,2-bis-4-hydroxycyclohexyl) propane, 2,4-dihydroxy-1,1,3,3-tetramethylcyclobutane, 2,2-bis (3-β-hydroxyethoxyphenyl) propane and 2,2- Bis- (4-hydroxypropoxyphenyl) propane (DE-OS 2 407 647, 2 407 776, 2 715 932).

The polyalkylene terephthalates can be branched by incorporating relatively small amounts of trihydric or tetravalent alcohols or trihydric or tetravalent carboxylic acids, as described in DE-OS 1 900 270 and US Pat. Examples of preferred branching agents are trimesic acid, trimellitic acid, trimethylolethane and -propane and pentaerythritol. It is advisable not to use more than 1 mol% of the branching agent, based on the acid component.

Particularly preferred are polyalkylene terephthalates which have been produced solely from terephthalic acid and its reactive derivatives (e.g. its dialkyl esters) and ethylene glycol and / or 1,4-butanediol and mixtures of these polyalkylene terephthalates.

Preferred polyalkylene terephthalates are also copolyesters which are produced from at least two of the alcohol components mentioned above: particularly preferred copolyesters are poly (ethylene glycol butanediol 1,4) terephthalates.

The preferably suitable polyalkylene terephthalates generally have an intrinsic viscosity of 0.4 to 1.5 dl / g, preferably 0.5 to 1.3 dl / g, in particular 0.6 to 1.2 dl / g, each measured in Phenol / o-dichlorobenzene (1: 1 parts by weight) at 25 ° C.

Suitable polyamides are known homopolyamides, copolyamides and mixtures of these polyamides. These can be partially crystalline and / or amorphous polyamides.

Polyamide-6, polyamide-6,6, mixtures and corresponding copolymers of these components are suitable as partially crystalline polyamides. Also suitable are partially crystalline polyamides, the acid component of which is wholly or partly composed of terephthalic acid and / or isophthalic acid and / or suberic acid and / or sebacic acid and / or azelaic acid and / or adipic acid and / or cyclohexanedicarboxylic acid, the diamine component wholly or partly of m- and / or p-xylylene diamine and / or hexamethylene diamine and / or 2,2,4-trimethylhexamethylene diamine and / or 2,2,4-trimethylhexamethylene diamine and / or isophorone diamine and the composition of which is known in principle.

Also to be mentioned are polyamides which are wholly or partly prepared from lactams with 7-12 C atoms in the ring, optionally with the use of one or more of the above-mentioned starting components.

Particularly preferred partially crystalline polyamides are polyamide 6 and polyamide 6,6 and their mixtures. Known products can be used as amorphous polyamides. They are obtained by polycondensation of diamines such as ethylene diamine, hexamethylene diamine, decamethylene diamine, 2,2,4- and / or 2,4,4-trimethylhexamethylene diamine, m- and / or p-xylylene diamine, bis- (4-aminocyclohexyl) - methane, bis- (4-aminocyclohexyl) propane, 3,3'-dimethyl-4,4'-diamino-dicyclohexylmethane, 3-aminomethyl, 3,5,5, -trimethylcyclohexylamine, 2,5- and / or 2, 6-bis (aminomethyl) norbornane and / or 1,4-diaminomethylcyclohexane with dicarboxylic acids such as oxalic acid, adipic acid, azelaic acid, azelaic acid, decanedicarboxylic acid, heptadecanedicarboxylic acid, 2,2,4- and / or 2,4,4-trimethyladipic acid, isophthalic acid and terephthalic acid.

Copolymers which are obtained by polycondensation of several monomers are also suitable, as are copolymers which are prepared with the addition of aminocarboxylic acids such as ε-aminocaproic acid, ω-aminoundecanoic acid or ω-aminolauric acid or their lactams.

Particularly suitable amorphous polyamides are the polyamides produced from isophthalic acid, hexamethylene diamine and other diamines such as 4,4'-diaminodicyclohexyl methane, isophorone diamine, 2,2,4- and / or 2,4,4-trimethylhexamethylene diamine, 2,5- and / or 2 , 6-bis (aminomethyl) norbornene; or from isophthalic acid, 4,4'-diamino-dicyclohexylmethane and ε-caprolactam; or from isophthalic acid, 3,3'-dimethyl-4,4'-diamino-dicyclohexylmethane and laurolactam; or from terephthalic acid and the isomer mixture of 2,2,4- and / or 2,4,4-trimethylhexamethylene diamine.

• 70 bis 99 Mol-% des 4,4'-Diamino-Isomeren
• 1 bis 30 Mol-% des 2,4'-Diamino-Isomeren
• 0 bis 2 Mol-% des 2,2'-Diamino-Isomeren und

gegebenenfalls entsprechend höher kondensierten Diaminen, die durch Hydrierung von Diaminodiphenylmethan technischer Qualität erhalten werden. Die Isophthalsäure kann bis zu 30 % durch Terephthalsäure ersetzt sein.Instead of the pure 4,4'-diaminodicyclohexylmethane, it is also possible to use mixtures of the positionally isomeric diaminodicyclohexylmethanes which are composed of one another

• 70 to 99 mol% of the 4,4'-diamino isomer
• 1 to 30 mol% of the 2,4'-diamino isomer
• 0 to 2 mol% of the 2,2'-diamino isomer and

if appropriate, correspondingly more highly condensed diamines obtained by hydrogenating technical-grade diaminodiphenylmethane. Up to 30% of the isophthalic acid can be replaced by terephthalic acid.

The polyamides preferably have a relative viscosity (measured on a 1% strength by weight solution in m-cresol at 25 ° C.) from 2.0 to 5.0, particularly preferably from 2.5 to 4.0.

The mixing of the individual components A, B and optionally C is possible in various ways.

The graft rubber components A) and B) are preferably isolated individually or after mixing on the latex stage by known processes, for example by spray drying or by adding salts and / or acids, washing the precipitated products and drying the powder. Then the graft rubber powders A) and B) (in the case of separate work-up) or the powder mixture (in the case of joint work-up) are optionally mixed with the resin component C) (preferably on multi-roll mills, mixing extruders or internal kneaders).

If the resin component C) was produced by emulsion polymerization, this latex can be mixed with the latex of components A) and B) and worked up together.

The necessary or appropriate additives, for example antioxidants, UV stabilizers, peroxide destroyers, can be added to the molding compositions according to the invention during production, workup, further processing and final shaping. Antistatic agents, lubricants, mold release agents, flame retardants, fillers or reinforcing materials (glass fibers, carbon fibers etc.), colorants.

The final deformation can be carried out on commercially available processing units and includes e.g. Injection molding processing, sheet extrusion with subsequent hot forming, cold forming, extrusion of pipes and profiles, calender processing.

In the following examples, the parts given are always parts by weight and the% given are always percentages by weight, unless stated otherwise.

Examples Graft rubber A

40 parts by weight (calculated as a solid) of an anionically emulsified polybutadiene latex produced by free-radical polymerization with ad ₅₀ value of 284 nm and a swelling index of 59 are brought to a solids content of approx. 20% by weight with water, followed by Heated 63 ° C and mixed with 0.5 part by weight of potassium peroxodisulfate (dissolved in water).

60 parts by weight of a mixture of 72% by weight of styrene and 28% by weight of acrylonitrile and 0.1 part by weight of tert-dodecyl mercaptan are then metered in over the course of 4 hours in such a way that the following contents occur in the course of the polymerization reaction unreacted monomer in the reaction mixture resulted (determined by sampling, addition of phenothiazine, coagulation of the polymer fraction and calculation of the unreacted amount of monomer): Sampling time (min after the start of the reaction) Proportion of unreacted monomer in the reaction mixture (% by weight based on the amount of monomer metered in) 20th 8.4 40 14.2 60 19.2 80 20.1 100 18.3 120 16.1 140 13.6 160 11.0 180 7.4 200 2.1 220 1.1 240 2.0 260 0.8 280 0.7 300 0.5

In parallel with the monomers, 1 part by weight (calculated as solid) of the sodium salt of a resin acid mixture (Dresinate 731, dissolved in alkaline water) is metered in as an emulsifier within 4 h. After a 1-hour post-reaction time, the graft rubber is coagulated with a mixture of aqueous magnesium sulfate solution and acetic acid after the addition of about 1.0 part by weight of a phenolic antioxidant; after washing with water, the resulting powder is dried at 70 ° C. in vacuo.

Graft rubber B1

50 parts by weight (calculated as a solid) of an anionically emulsified polybutadiene latex with a d ₅₀ value of 128 nm, produced by radical polymerization, are brought to a solids content of approx. 20% by weight with water, then heated to 63 ° C. and 0.5 parts by weight of potassium peroxodisulfate (dissolved in water) is added.

50 parts by weight of a mixture of 72% by weight of styrene and 28% by weight of acrylonitrile are then metered in over the course of 6 hours in such a way that the monomers react evenly during the course of the reaction. Parallel to the monomers, 1 part by weight (calculated as solid substance) of the sodium salt of a resin acid mixture (Dresinate 731, dissolved in alkaline water) is metered in as an emulsifier within 6 h. The processing is carried out as described under A.

Graft rubber B2

55 parts by weight (calculated as a solid) of an anionically emulsified polybutadiene latex having a d ₅₀ value of 412 nm and produced by free-radical polymerization are brought to a solids content of approx. 20% by weight with water, then heated to 62 ° C. and 0.5 parts by weight of potassium peroxodisulfate (dissolved in water) is added.

45 parts by weight of a mixture of 72% by weight of styrene and 28% by weight of acrylonitrile are then metered in over the course of 6 hours in such a way that the monomers react uniformly during the course of the reaction. The other conditions (emulsifier, processing) correspond to those in B1.

Thermoplastic resin C1

_w = 85.000, $\overline{\text{M}}$

_w/ $\overline{\text{M}}$

_n-1 ≦ 2)Styrene / acrylonitrile copolymer resin (styrene: acrylonitrile weight ratio = 72:28, $\overline{\text{M}}$

_w = 85,000, $\overline{\text{M}}$

_w / $\overline{\text{M}}$

_n -1 ≦ 2)

Thermoplastic resin C2

_w = 115.000, $\overline{\text{M}}$

_w/ $\overline{\text{M}}$

_n-1 ≦ 2).Styrene / acrylonitrile copolymer resin (styrene: acrylonitrile weight ratio = 72:28, $\overline{\text{M}}$

_w = 115,000, $\overline{\text{M}}$

_w / $\overline{\text{M}}$

_n -1 ≦ 2).

Thermoplastic resin C3

_w = 80.000, $\overline{\text{M}}$

_w/ $\overline{\text{M}}$

_n-1 ≦ 2).α-methylstyrene / acrylonitrile copolymer resin (weight ratio α-methylstyrene: acrylonitrile = 72:28, $\overline{\text{M}}$

_w = 80,000, $\overline{\text{M}}$

_w / $\overline{\text{M}}$

_n -1 ≦ 2).

ABS molding compounds

The polymer components described above were mixed in the proportions given in Table 1 in an internal kneader, with 2 parts by weight of pentaerythritol tetrastearate, 0.1 part by weight of a silicone oil and 1 part by weight of a carbon black as additives in Examples 1 to 4 were added. In Examples 5 to 10, 1 part by weight of pentaerythritol tetrastearate, 0.5 part by weight of magnesium stearate and a colorant (0.93 part by weight of a blue color mixture in Examples 5 to 7, 1 part by weight) were used as additives of a carbon black in Examples 8 to 10).

After granulation, the molding compounds were injection molded into test bars and into a special plate with ribs (to assess the color depth).

The following data were also determined:
Notched impact strength at room temperature (a _k ^RT ) and at -40 ° C (a _k ^{-40 ° C} ) according to ISO 180 / 1A (unit: kJ / m ² ), ball indentation hardness H _c according to DIN 53 456 (unit: N / mm ² ), heat resistance (Vicat B) according to DIN 53 460 (unit: ° C), flowability MVI according to DIN 53 735 U (unit: cm ^3/10 min).

• 1: sehr schwach bis nicht erkennbar
• 2: schwach
• 3: mittel
• 4: stark
• 5: sehr stark

The color deepening was assessed visually according to the following gradation:

• 1: very weak to not recognizable
• 2: weak
• 3: medium
• 4: strong
• 5: very strong

The results are summarized in Table 2. It can be seen from this that the molding compositions according to the invention have very good mechanical values with only a very slight color deepening.

For illustration, an electron micrograph was taken of a molding compound according to the invention (Example 8) (contrasting with osmium tetroxide) (Figure 1). Table 1 Compositions of the molding compositions investigated E.g. Graft rubber A parts by weight Graft rubber B1 parts by weight Graft rubber B2 parts by weight Thermoplastic resin C1 parts by weight Thermoplastic resin C2 parts by weight Thermoplastic resin C3 parts by weight 1 37.5 - 9.1 - 53.4 - 2nd 25th - 18.2 - 56.8 - 3 (comparison) 50 - - - 50 - 4 (comparison) - - 36.4 - 63.6 - 5 27 4.5 4.5 34 - 30th 6 (comparison) - 4.5 24.5 41 - 30th 7 (comparison) 39 - - 31 - 30th 8th 27 4.5 4.5 34 - 30th 9 (comparison) - 4.5 24.5 41 - 30th 10 (comparison) 39 - - 31 - 30th Test data of the molding compounds examined E.g. a _k ^RT (kJ / m ² ) a _k ^{-40 ° C} (kJ / m ² ) H _c (N / mm ² ) Vicat B (° C) MVI (cm ^3/10 min) Deepening of color 1 38 23 88 99 6 2nd 2nd 35 21 88 98 6 1 3 (comparison) 40 24th 86 99 6 5 4 (comparison) 30th 18th 88 99 7 3rd 5 21 9 98 106 9 2nd 6 (comparison) 17th 7 100 107 9 3rd 7 (comparison) 22 9 98 105 8th 4th 8th 20th 9 101 104 8th 1 9 (comparison) 17th 7 99 105 9 3rd 10 (comparison) 21 9 100 104 8th 4th

Claims (5)

Containing thermoplastic molding compounds A) 5 to 95 parts by weight of at least one particulate graft rubber polymer of the ABS type produced by emulsion polymerization, in which the graft rubber particles have such a structure that can be detected by transmission electron micrographs, in which the individual particles contain uneven cellular inclusions of resin-forming polymer and the surface of the Particles such an irregularly serrated structure shows that there are 5 to 30 such serrations per imaged particle, which differ from an idealized round particle (with a diameter d) through a diameter $\text{d + d / x with x = 3 to 15}$

distinguish, B) 95 to 5 parts by weight of at least one particulate graft rubber polymer of the ABS type produced by emulsion polymerization, in which the graft rubber particles have a structure which can be detected by transmission electron microscopy, in which the individual particles have no pronounced internal structure as in A) and a round one Show particle shape with a completely jag-free surface and if necessary C) 0 to 300 parts by weight of at least one thermoplastic rubber-free resin. Thermoplastic molding compositions according to claim 1, containing A) 10 to 80 parts by weight of at least one particulate graft rubber polymer of the ABS type produced by emulsion polymerization, in which the graft rubber particles have a structure which can be detected by transmission electron microscopy, in which the individual particles have non-uniform cellular inclusions of resin-forming Contain polymer and the surface of the particles shows such an irregularly serrated structure that there are 7 to 25 such serrations per imaged particle, which differ from an idealized round particle (with a diameter d) by a diameter $\text{d + d / x with x = 4 to 12}$

distinguish, B) 90 to 20 parts by weight of at least one particulate graft rubber polymer of the ABS type produced by emulsion polymerization, in which the graft rubber particles have such a structure that can be detected by transmission electron microscopy, in which the individual particles have no pronounced internal structure as in A) and a round one Show particle shape with a completely jag-free surface and if necessary C) 20 to 250 parts by weight of at least one thermoplastic rubber-free resin. Thermoplastic molding compositions according to claims 1 and 2, characterized in that the particulate graft rubber polymers consist of polybutadiene and a grafted copolymer of styrene and acrylonitrile. Thermoplastic molding compositions according to claims 1 to 3, characterized in that the thermoplastic component C contains at least one resin selected from styrene / acrylonitrile copolymer, α-methylstyrene / acrylonitrile copolymer, aromatic polycarbonate, aromatic polyester carbonate, polyester, polyamide. Use of the thermoplastic molding compositions according to claims 1 to 4 for the production of molded parts.

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